中文摘要：

利用多波束测深系统对长江口南港、北槽、横沙通道和北港水下地貌进行测量，对沙波波高、波长、迎流倾角、背流倾角、水深和沉积物特征进行统计，并根据流速、沉积物粒径及水深估算其潮周期内净位移。结果表明：长江口沙波基本都为大型沙波，且沙波大小与其所在区域沉积物粒径呈正比关系；长江口各个区域沙波的对称性不同，涨、落潮优势流越明显，则沙波对称性越差，净位移越大；沙波对称性能反映此区域水动力强弱及潮周期内沙波净位移大小。

英文摘要：

The underwater topography at the South Channel, North Passage, Channel of Hengsha and North Channel of the Yangtze Estuary were surveyed by using multibeam echo-sounding system,wave height, wavelength,inflow angle, the dorsal stream angle and sediment characteristics of sand waves in these areas were calculated statistically, and the net displacement of sand waves in one tidal period was estimated on the basis of data for flow rate,grain si- zes of sediments and water depths. The results showed that the sand waves in the Yangtze Estuary were basically large, and there took on a proportional relationship between wavelengths with sediment particle sizes. The symme- try of sand waves is different among all surveyed area in the Yangtze Estuary. The more obvious the ebb flow is, the worse the symmetry of sand wave and the more net displacement is. The symmetry of sand waves can reflect the power of water and net displacement of sand waves.